US in contact with N. Korea, probing willingness to talk: Tillerson

US Secretary of State Rex Tillerson (left) shakes hands with Chinese President Xi Jinping before their meeting at the Great Hall of the People in Beijing, on September 30, 2017

The United State has open channels of communication with North Korea and is investigating whether the regime is ready to enter talks on giving up its nuclear weapons programme, US Secretary of State Rex Tillerson said Saturday.

Tillerson's disclosure follows an escalating war of words between US President Donald Trump and North Korean strongman Kim Jong-Un.

"We are probing, so stay tuned," he told reporters after talks with Chinese officials in Beijing. "We ask. We have lines of communication with Pyongyang. We're not in a dark situation, a blackout, we have a couple, three channels open to Pyongyang."

"We can talk to them, we do talk to them," he said.

Asked whether China was acting as a go-between for the contacts, Tillerson said: "Our own channels."

Tillerson spoke after an afternoon of talks with China's top diplomats and President Xi Jinping centred on the nuclear crisis and preparations for Trump's visit to Beijing in November.

Before Tillerson revealed the diplomatic opening, a North Korean state body that handles external propaganda lobbed a new insult at Trump, calling the US leader an "old psychopath" on "a suicidal act of inviting a nuclear disaster that will reduce America into a sea of flames".